Pump



Jlilnall, 1940- R. A. WElNHARDi' 2,203,974

PUMP

Filed Feb. 8, 1937 IgENTOR.

Patented June 11,1940

UNITED STATES PUMP Robert A. Weinhardt. Lansing, Mich, assignor of one-fourth to Herbert B. Trix,

one-fourth to John A Kienle, andone-fourth to Alfred Vang, all of Wayne County, Mich.

Application February 8, 1937, Serial No. 124,543

4 Claims. (Cl. 103-140) Fig. is a view similar to that of Fig. 4 but This invention relates to pumps and particularly to rotary pumps for the delivery of liquids under pressure.

In rotary pumps of this character heretofore employed, difliculty has been encountered in preventing both internal and external leakage. Internal leakage is usually the result of the operat ing clearances necessarily provided between the rotor and the pump cavity, and external leakage ls usually caused by the failure of packing materials between the pump head and the rotor and around the shaft bearings. I

When pumps of this character are employed to force gasoline or other volatile liquids from supply tanks to internal combustion engines, the above-mentioned internal leakage has been a source of serious diificulty due to a condition commonly known as vapor lock. This condition occurs when the temperature of the gasoline is sufllciently high to cause partial volatilization thereof and a perfect seal is not formed between thepump rotor and the walls of the pump cavity permitting vapor instead, of liquid gasoline to be induced into the pump and forced therefrom to the engine, causing the engine to cease operation as is well known.

Itis, therefore, an object of the present invention to provide a. rotary pump wherein no clearance is provided between the relatively moving parts, thus preventing internal leakage.

It is another object of the invention to provide a pump of the above character which is self-sealing, thus obviating the use of packing materials previously employed to prevent external leakage.

Another object of the invention is to provide a pump rotor which is self-sealing against leakage.

Still another object of the invention is to provide a pump rotor formed of resilient material.

A further object of the invention is to provide a pump rotor having resilient blades adapted to engage the walls of the pump cavity.

Other objects and advantages of the invention will become apparent from a reading of the following description taken in connection with the accompanying drawing in which,

Fig. 1 is a longitudinal sectional view of a rotary pump embodying the present invention.

Fig. 2 is a sectional view taken substantially on the lines 2-2 of Fig. 1 and looking in the direction indicated. a a

Fig. 3 is a view similar to. that of Fig. 2 but showing the pump rotor in a different angular position.

Fig. 4 is a view of the pump rotor shown in Figs. 1, 2 and 3, and

, perfect seal against internal leakage.

showing a modified form of the pump rotor.

Referring now to the drawing, reference numeral It) indicates a pump casing having a bearing portion I I to receive a rotatable shaft l2 which may be driven by any suitable means and which extends through the bearing ll interiorly of the casing Hi to a pump cavity l3 formed therein.

The pump rotor l4 comprising the present invention is bonded or otherwise suitably secured to the end of the shaft I2 within the cavity 13 to rotate with the shaft, and it will be noted that the axes of the shaft l2 and the rotor M are arranged in eccentric relation to the axis of the cavity l3.

A suitable head I6 is removably secured to the casing to form a-clcsure for the cavity i3 and is provided with inlet and outlet ports I! and I 8 and connecting conduits l9 and leading to the exterior thereof.

The rotor I4 is preferably formed of a resilient material which is impervious to the action of gasoline, oil, alcohol, benzol and similar liquids and which retains its resiliency when operated in such liquids. Rubber, synthetic rubber or the various Well-known substitutes therefor, such as Du Prene or Thiokol, are all suitable materials. As shown, the rotor is annular in form with the inner periphery thereof in bonded engagement with the shaft l2 and is of a thickness at least equal to the depth of the pump cavity l3 and preferably slightly thicker. The rotor I4 is formedwith flat faces 2| and 2'2 closely engaging the flat wall of the cavity I3 and the inner face of the head l6, forming a tight seal against external leakage of liquid from the cavity l3.

As shown, the rotor 14 is somewhat smaller in diameter than the cavity I3 and is provided on its periphery with resilient blades 23 and 24 which may be arranged diametrically opposite each other to yieldably engage a portion of the peripheral wall of the cavity l3 at all times, forming a The outer cylindrical surfaces of the rotor l4 intermediate the blades 23 and 24 are in substantially tangential contact with the nearer portion of the casing l0 which is between the inlet and outlet ports l1 and Ill. The rotor may be formed with the blades in the position shown in Fig. 4 and compressed when placed in the cavity [3.

The amount of delivery pressure obtainable by the pump is determined by the resiliency of the blades 23 and 24. By proper selection of the material forming the rotor and by varying the size of the blades, any desired pressure capacity may be obtained.

In some instances it may be desirable to provide yieldable metal inserts 26 for the blades 23 and 24 by imbedding such inserts in the material forming the rotor. As shown in Fig. 5, one end of the inserts may be imbedded in the body of the rotor as at 21 and the free end thereof may extend substantially the length of the blades. This construction will increase the pressure of the blades on the peripheral wall of the cavity l3 and correspondingly increase the pressure output of the pump.

In operation, assuming the rotor to be rotating in the direction of the arrows in Figs. 2 and 3, the tips of the blades 23 and 24 will closely engage and follow the peripheral wall of the cavity l3 and thus the size and capacity of the space S in Fig. 2 will be gradually increased while the size and capacity of the space P will be gradually decreased due to the eccentric relation of the rotor and the cavity. As the liquid is induced through the passageway l9 and port I! into the cavity l3 and space S between the rotor I4 and the peripheral wall of the cavity l3, it will be forced clockwise by the blade 23 in Fig. 3 and expelled through port l8 and passageway 20. Fig. 2 illustrates the manner in which the blades 23 and 24 are received in complemental recesses formed in the rotor M. Fig. 4 indicates the profile and Fig. 1 the extent of the slots or grooves which separate the blades 23 and 24 from the rotor i4.

As the resistance to the outgoing fluid may be increased, as by increasing the closure of the outlet piping by a valve or other means, a backpressure will be built up suflicient to overcome the resiliency of the blades 23 and 24 causing them to yield and permit a slippage of the liquid backward from the pressure side P to the inlet side S, and if the outlet should be entirely closed, the pump would cease to discharge liquid but will continue to rotate.

It will thus be seen that a rotary pump has been provided which obviates the necessity of packing materials usually necessary to prevent external leakage and is constructed in such a manner as to prevent internal leakage.

It will be apparent to those skilled in the art that various modifications in construction and design may be made without departing from the spirit or scope of the invention as defined by the appended claims.

What is claimed and desired to be secured by Letters Patent is:

l. A rotary displacement pump comprising a casing having inlet and outlet ports, a rotor body within said casing in tangential contact with the wall thereof between the inlet and outlet ports, and an integral blade extending from the rotor body and having a free end engaging the wall of said casing, said blade being of suificient resiliency to yield toward said rotor body under a predetermined amount of back pressure of the fluid being pumped.

2. A rotary displacement pump comprising a casing having inlet and outlet ports, a rotor body within said casing in tangential contact with the wall thereof between the inlet and outlet ports, in integral blade extending from the rotor body and having a free and engaging the wall of said casing, and a resilient member connected to the rotor and the blade, said blade being of sufficient resiliency to yield toward said rotor body under a predetermined amount of back pressure of the fluid being pumped.

3. A rotary displacement pump comprising a casing having inlet and outlet ports, a rotor body within said casing in tangential contact with the wall thereof between the inlet and outlet, ports, and integral blades extending tangentially from the rotor body and having free ends engaging the wall of said casing, said blades being of sufficient resiliency to yield toward said rotor body under a predetermined amount of back pressure of the fluid being pumped.

4. A rotary displacement pump comprising a casing having inlet and outlet ports, a rotor body within said casing in tangential contact with the wall thereof between the inlet and outlet ports, integral blades extending tangentially from the rotor body and having free ends engaging the wall of said casing, and resilient members extending from the rotor body into the blades and completely embedded therein, said blades being of sufiicient resiliency to yield toward said rotor body under a predetermined amount of back pressure of the fluid being pumped.

ROBERT A. WEINHARDT. 

